Using screw piling as a method for underpinning a foundation is a really cost effective and less intrusive way of securing property subsidence to stop any further movement due to moisture loss in the ground, trees or roots growing larger over time absorbing substantial volumns of water from the ground. Other potential causes can be broken drains, gutters or soakaways that have cracked, failed or become blocked.
If you find gaps, cracks or uneven surfaces your property is likely to be affected. Looking at points of load where there could be weaknesses such as around doors and windows; if they become sticky or tight to open / shut will help give an indication.
Our screw piling foundation system is highly suited to an underpinned foundation solution. Especially when tight access limits getting in with a larger machine to do any excavation.
Ultimate Screw Piling have recently completed two underpinning projects in the last few weeks; the first project - access was brilliant and we were able to incorporate the underpinning with a new reinforced slab. The second project, access was so limited so we used our micro digger in order to excavate the required access to the existing property foundations that needed support.
In many cases our installers have to cut out access locations in existing concrete slabs / concrete paths etc. Once this has been done, as much excavation as possible is done with our micro digger, then finishing off the excavation by hand, in order to get enough excavated space beneath existing foundations. This allows our team to install our screw pile as close to the property as possible. Once the required torque setting has been achieved as set out by our engineering team, we slide our custom underpinning bracket onto the screw pile shaft, then torque up the bolted connection to pull the bracket as tight under existing foundations as possible.
Where possible, depending on existing foundation make up / construction, we would bolt our underpinning bracket to the foundations using an M20 resin bolted connection.
As an additional measure we will then encase the screw pile underpin cap within crushed material or concrete to prevent any further movement of the building. This will be a decision made by our engineer based on ground conditions at the time, post excavation.
Two stages showing our underpin pile caps - image 1 is the custom underpinning bracket that fits under the existing foundations, image 2 is the top bracket mounted on top of the pile that shows the M24 8.8 grade BZP bolts that have been torqued up to hold everything in place.
Images above show the screw piling foundations for the new base installed on the front extension of the property. The underpinning solution was installed to the right on the small nib of the existing building. The screw piles used in this foundation solution for both the new reinforced concrete slab and the underpinning were our 50R mini screw piles.
If you have any signs of subsidence or cracks in your building, please get in touch and we can help you with a cost and time effective solution.
Email us: sales@ultimatescrewpiling.co.uk
